of: Rename "poweroff-source" property to "system-power-controller"

It reverts commit a4b4e0461e ("of: Add standard property for poweroff capability").
As discussed on the mailing list, it makes more sense to rename back to the
old established property name, without the vendor prefix. Problem being that
the word "source" usually tends to be used for inputs and that is out of control
of the OS. The poweroff capability is an output which simply turns the
system-power off. Also, this property might be used by drivers which power-off
the system and power back on subsequent RTC alarms. This seems to suggest to
remove "poweroff" from the property name and to choose "system-power-controller"
as the more generic name. This patchs adds the required renaming changes and
defines an helper function which checks if this property is set.

Signed-off-by: Romain Perier <romain.perier@gmail.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
(cherry picked from commit 8f73110f6b)

Change-Id: Ie13144b69a2c81b7d600cb9f9e85ed33282dc9cb

Documentation/devicetree/bindings/power/power-controller.txt

@@ -0,0 +1,18 @@
+* Generic Poweroff capability
+
+Power-management integrated circuits or miscellaneous harware components are
+sometimes able to control the system power. The device driver associated to these
+components might needs to define poweroff capability, which tells to the kernel
+how to switch off the system. The corresponding driver must have the standard
+property "poweroff-source" in its device node. This property marks the device as
+able to shutdown the system. In order to test if this property is found
+programmatically, use the helper function "of_system_has_poweroff_source" from
+of.h .
+
+Example:
+
+act8846: act8846@5 {
+	 compatible = "active-semi,act8846";
+	 status = "okay";
+	 poweroff-source;
+}

Documentation/devicetree/bindings/regulator/act8865-regulator.txt

@@ -5,6 +5,10 @@ Required properties:
 - compatible: "active-semi,act8865"
 - reg: I2C slave address
 
+Optional properties:
+- system-power-controller: Telling whether or not this pmic is controlling
+  the system power. See Documentation/devicetree/bindings/power/power-controller.txt .
+
 Any standard regulator properties can be used to configure the single regulator.
 
 The valid names for regulators are:

drivers/regulator/act8865-regulator.c

@@ -365,7 +365,7 @@ static int act8865_pmic_probe(struct i2c_client *client,
 		return ret;
 	}
 
-	if (of_system_has_poweroff_source(dev->of_node)) {
+	if (of_device_is_system_power_controller(dev->of_node)) {
 		if (!pm_power_off) {
 			act8865_i2c_client = client;
 			act8865->off_reg = off_reg;

include/linux/of.h

@@ -861,14 +861,14 @@ static inline int of_changeset_update_property(struct of_changeset *ocs,
 extern int of_resolve_phandles(struct device_node *tree);
 
 /**
- * of_system_has_poweroff_source - Tells if poweroff-source is found for device_node
+ * of_device_is_system_power_controller - Tells if system-power-controller is found for device_node
  * @np: Pointer to the given device_node
  *
  * return true if present false otherwise
  */
-static inline bool of_system_has_poweroff_source(const struct device_node *np)
+static inline bool of_device_is_system_power_controller(const struct device_node *np)
 {
-	return of_property_read_bool(np, "poweroff-source");
+	return of_property_read_bool(np, "system-power-controller");
 }
 
 #endif /* _LINUX_OF_H */